Not Mine But The One I Choose
by TheOneWithWheelsASH
Summary: Sherlock's daughter has a very important question to ask Molly. Originally posted on Archive Of Our Own


When Sherlock's daughter Lillian Holmes came up to Molly with a letter, some paperwork and a question, she was very taken back. To Molly, Lillian was still that little girl that she found on the doorstep of Baker Street all those years ago.

The night was just like any other night at Baker Street. It was nearing midnight; Molly was sat on the sofa in the living room reading while Sherlock was sat working on an experiment at the kitchen table. Molly was staying at Sherlock's because her flat had flooded. It had been a few months since THAT phone call and things were slowly starting to get back to normal between the two of them. At this moment in time they were just concentrating on being friends. If something happened between the two of them later on, they would cross that bridge when they come to it. But, for now, they were quite happy.

It was nearing midnight and Molly decided that it was probably was time to put the book down and go to bed; even though she didn't have work the next day she knew she needed the sleep.

"Night, Sherlock," Molly said before leaving the room.

"Goodnight, Molly, sleep well."

As she was making her way up to John's old room, she heard a knock on the main front door. Knowing that Sherlock would not get the door and, with Mrs Hudson being away, it was up to her to get it. She silently hoped it wasn't a client. She didn't think she could deal with Sherlock in case mood right now.  
When she opened the door she was shocked at what she saw. There on the door step was a baby in wrapped in a bundle of blankets with a little envelope just tucked inside. It briefly reminded Molly of Harry Potter. She quickly picked the baby up and made sure not to wake the child in the process.

She didn't know what to do at first. Why would someone leave a baby on a doorstep? Why would someone leave a baby on Sherlock's door step? Molly walked the stairs to Sherlock's flat. He had moved since she'd left the flat; she guessed that he was in the bathroom, considering his bedroom door was still open. A moment later he walked out bathroom door and stood dead in his tracks at the sight he saw. Molly holding a baby. It wasn't Rosie - too small to be her. Who could it be and where did it come from?

"I thought you were going to bed?" was all the only words Sherlock could get out.

"I was, but then I heard a knock on the front door, so I went and answered it and all that was there was this little one," Molly said, gesturing to the sleeping baby in her arms.

"Nobody else around?"

Molly shock her head.

Sherlock quickly ran to his room to retrieve the Moses basket he kept for when Rosie was around. He brought it back into the living room, setting it down for the child to sleep in it. Molly laid the child down and slowly pulled out the envelope that was tucked inside the blanket. She handed it to Sherlock, knowing that it was best that he was the one to read it. He would get the most out of it. He took it from her and opened it up. Inside was a birth certificate and a letter.

"What is it?" Molly asked.

"A birth certificate, and a letter."

"What does the letter say?"

"I don't know - give me a chance to read it, will you?" Sherlock responded with.

He sat down and began to read the letter.

 _Hello,_

 _You probably don't remember me. We only met once, one night, and you were very drunk. A result of that night is the baby I left on your doorstep. Your baby. Your daughter. I am not able to look after her, for many reasons - plus I don't think I can be the mother she needs. I have signed over any parenting rights I have. Don't think I'm doing this because I don't love her. It's quite the opposite. I do love her but she is better with you._

 _Thanks,_

 _Annie_

Sherlock looked up from the letter. He was slowly starting to let it sink in. He had a child.

"It would seem this child is mine," Sherlock announced.

"What? Really? How did that happen? Where did she come from?" Molly asked, shocked.

"Really, Molly, as someone with a medical background, you should know that".

"Sherlock, you know what I mean," she said, giving him a very stern look.

"I'm guessing it happened on Greg's stag night. The letter said I was very drunk, and that was the very last time ... Well, you know."

"Oh, Sherlock," Molly said, a little bit shocked. "What else does the letter say? Does it say anything about how we can help him back to his mother?"

"Her, Molly, she's my daughter," Sherlock said, surprised at the sound of those word coming out of his mouth. "And no, the mother has only left a name. It says she can't be a mother to the child and that she is better off with me."

"So what are you going to do?"

"What do you mean, what am I going to do?" Sherlock asked "I can't keep her. She's only in this world because of a moment of weakness, because I got stupidly drunk. You know my life, Molly. I can't be a father to her."

"Sherlock," Molly said, raising her voice but not enough that it would wake her. "You're a grown man. Take some responsibility. She's your child. Have you even looked at her?"

He turned his back to Molly and his daughter. Molly once again picked up the sleeping baby and took her to Sherlock.

"Look Sherlock, look at her. She's so beautiful, she's yours, and she needs you."

He turned round to look at Molly and the child in her arms. Molly slowly started to put the baby in his arms. As he started to relax the child slow started to wake up, opening her eyes and looking at her dad for the very first time. Molly couldn't get over the look on Sherlock's face. There was a smile so big, and tears running down his face. Parenting instinct kicked in and he hushed her back to sleep. He kept her in his arms as she stayed asleep. He didn't want to let her go.

Molly sat down in John's chair opposite Sherlock.  
"Does she have a name?" Molly asked.

"No, the mother didn't give her one, or if she did she didn't write it down." He looked back once again at the letter and the birth certificate but it was blank. "I guess I'll have to come up with one. Can't call her she, or the child, for the rest of her life."

"No, I guess not. Do you have any ideas?"

"Lilian," he said, without looking up from his daughter. "After my grandmother, and it's also my mother's middle name".

"How lovely, Sherlock. Look, I should probably run to Asda quickly; it's open 24 hours. We have nothing in your flat that Lillian needs. I'll be quick, I'll pick up some nappies, bottles, Baby formula, and maybe a couple change of clothes. She has nothing else with her and, if I remember the early days with Rosie, babies need a number of different clothes because they tend to get messy."

"Don't be long. I might need you," Sherlock said.

"I won't be gone long. 20 minutes at most. How much trouble can you get into in that time? Also, maybe you should text Mycroft and let him know the situation. You might not think, but you need him."

Molly quickly put a coat on and some shoes whilst calling a taxi. She left Sherlock and Lillian at Baker Street. She looked at her watch - 12:30am. So much had changed in half an hour.

When she got into the supermarket, she picked up the items she went for. But, when she was picking out a few clothes, something caught her eye. In the aisle opposite her were toys. She walked down it and saw the toy that caught her eye. It was a teddy. It was creamed coloured, it was nothing special, but Molly bought it anyway.

She bought everything she needed and got another taxi back to Baker Street. When she walked through the front door, she was met with a crying sound. She rushed upstairs to see what was wrong. When opening the door to Sherlock's, she saw a frantic Sherlock trying to calm Lillian down.

"What took you so long? You said you'd only be 20 minutes - you were gone 28 and half minutes. She started crying 5 minutes after you left. That's 23 minutes of me trying to settle her but it's not working".

Molly giggled to her amusement at the way Sherlock was acting. "Sorry. Traffic took longer than expected. Pass her here, and you can go through the items that I bought".

Sherlock passed Molly Lillian while he unpacked everything. Molly started to work out what was wrong with the child. She wasn't wet or smelly, so she didn't need her nappy changing. So she guessed that she was hungry. Sherlock was one step ahead of her, already preparing a bottle.

When it was done, Molly passed Lillian back to Sherlock, and he stared to feed her. Molly just sat and watched what was happening.

"Did you text Mycroft?" Molly questioned.

"Yes, I did. He said he'd be over first thing in the morning to talk to us so we can start planning schedules. He's also going to make sure we have all the baby equipment".

"Oh, that's nice ...Wait, Sherlock, did you just say he'd be over to talk to ****us**** ... And **we'd** have all the baby equipment?"

"I did. You heard me perfectly fine. Your hearing is very good, Molly, don't question it".

"But you don't really need me here."

"Oh, but I do," Sherlock said. "I've already started sorting it with Mycroft. We think it would be best if you moved in to 221C. Mrs Hudson made Mycroft pay for it to get fixed after the explosion as a way of apology. It hasn't got on the market yet, but Mrs Hudson will be okay with it - just as long as it's okay with you."

"It's okay. I can help with Lillian, if you want. Baker Street is nearer to Bart's than where I live. But, are you sure this is okay with you?" Molly enquired.

"To tell you the truth, since you've been staying here, I've enjoyed your company and I didn't want you to leave. I like having you here."

"I've liked being here."

They both turned their attention back to the baby in Sherlock's arms, who was now fast asleep.

In the morning was when things got busy. Mycroft came over and stared planning things: Molly would be moved in by the end of that week, Mycroft also got her the rest of that week off so she could sort things out. Also all the baby things would be there by the afternoon.

Sherlock also texted Greg and John to let them know about his situation.

 ** _ **'John: I have a daughter. Please come if convenient. If inconvenient come anyway-SH'**_** ****

 ** _ **'Greg: won't be able to take any case for a few days. I've got a daughter. Hope you're able to cope without me - SH**_** '

When they read those texts, they could not believe what was written. Sally and Anderson (who got his job back) both thought it was some joke.

When everything had been sorted and arranged, Sherlock invited people over to meet his daughter. John brought Rosie (he hoped when they both got older they'd be friends) Mrs Hudson joined in too, liking the fact that there was a baby in Baker Street. Greg came with his new wife. Mike Stamford also turned up. Anderson and Sally also wanted to see the child, and, last but not least, Sherlocks parents. Mycroft invited them, which Sherlock was not happy about.

Everybody couldn't believe how brilliant Sherlock was at being a dad; in the few hours that they were there, they knew that Lillian was going to be okay. Especially with Molly by his side. When they both went out the room, everyone started a bet at how long it would be until they were finally in a relationship, or realised that they basically were already.

As a few years went by, nothing much changed. Sherlock still went out and solved his cases, Molly still had her job at Bart's, and they still lived together at Baker Street. It wasn't a normal family, but they weren't normal, and it worked for them.

Lillian was just like her farther - not just in looks but she was smart too. When she first started talking, she was calling Molly mum. It's not that Molly didn't fit that role, but she didn't want to replace the role of a woman who wasn't there.

They told Lillian early on that Molly wasn't her mother, but it didn't mean that Molly didn't love her any less. Molly loved Lilly (as she liked to call her) as if she was her own.

Whenever Lillian had a nightmare, she'd grab the teddy bear she'd had for as long as she could remember and go straight to Molly. She always knew how to make her feel better. She'd always have a story to tell, to calm her down. She'd liked going to Molly's flat when having a nightmare for another reason and that was the fact that her dad always seemed to be there.

When it was time for starting school, Molly made sure she was at every school (not just to make sure Sherlock behaved himself), every parents' evening and sports day, and whatever else she could go to.

When Lillian got older, she went on cases with her dad and enjoyed it. She didn't mind watching Molly perform an autopsy; she found it fascinating. She got on well with most of her parent's friends.

John was Uncle John for as long as she could remember. Rosie and Lily had been friends since day one; they were in the same class at school and they were a force to be reckoned with. Greg was always the fun uncle; he always made sure that she was sweet on him whenever he went to Sherlock with a case. Anderson and Sally also didn't mind having her around; she might have been as smart as her dad, but she had Molly's kindness. Anderson was a big fan of her, which annoyed Sherlock to no end. Mrs Hudson was like another grandparent; she loved her very well She got on well with her Uncle Mycroft; by the age of three, she knew how to wrap him round her little finger.

Mycroft was the only person that called her by the name of Lillian. Everybody either called her Lil or Lilly. Sherlock did use those names, but his main nickname for her was always sweetheart. Mrs Hudson always called her dear. Her grandparents would always call her darling; she would always spend Christmas at their houses.

As time went on, Lillian did feel a little different to her other classmates. She didn't know what it was until, one day, her friends started talking.

"We're going out for dinner, and I'm buying her some flowers tomorrow," Amber, one of her friends, said.

"We're making breakfast in bed, and doing a movie day, and I've also made her a card." Jessica, her other friend, said. "Lil, what are you getting your mum for Mother's Day?".

The question caught her off guard. "I'm not... I mean, I don't do Mother's Day. I don't know who my mum is."

"But I met your mum just before Christmas. She's really nice," Amber said.

"Oh, that's not my mum, that's Molly. I guess you could say she's been the most like a mum to me".

"You do know that DNA doesn't matter? In my mind, if she does everything a mother would do, then she's your mum," Jessica said.

These word rang in her mind all the way home. When she got in, she was surprised to see her father sat in his chair, reading the paper. She knew Molly was at Bart's until at least dinner time; she had enough time to talk to her dad. Sherlock knew the minute his daughter sat down opposite him something was wrong.

"What's wrong, sweetheart?" He asked.

"Dad, why doesn't Molly want to be my mum? Why doesn't she want me to call her Mum?"

Sherlock had wondered the same thing many a time over the years. He asked her once, one evening in her flat, when they were slow dancing to a piece of music he had composed.

"Molly, why don't you let Lillian call you Mum? You technically are. She loves you. She want to call you Mum."

"It's because I don't want to replace someone she doesn't know. One day she might want to find her mum, and who am I to stop her?"

"Dad."

Sherlock was snapped out of his memory.

"I think she's worried she's filling a gap of someone who's not there."

"But, Molly's been my mum for as long as I can remember."

"I know," Sherlock replied.

"Dad, I've been thinking. I want Molly to adopt me ...what do you think?"

"I like that idea very much. I'll get Mycroft to send over the paperwork. Maybe you should write Molly a letter, asking her. It's Mother's Day this weekend, so maybe you could give it to her then."

"Yes, Dad! That's a brilliant idea." Lillian got up, kissed on the forehead, and ran up stairs to her and set too work on the letter.

On Mother's Day she walked down the stairs to 221C and handed it all to Molly. Molly was confused at what it all was Lillian sat down opposite her as Molly began to read.

 _Dear Molly,_

 _For as long as I can remember, you've been there for me. You were the one who found me and brought me into the crazy world that is living with Dad._

 _He told me once that if it wasn't for you, he probably would have given me up. He said that you were the first one to believe in him. He said that if you hadn't made him hold me, then he wouldn't have given me a chance, given us a chance._

 _You've always been there. If I feel down, you'd pick me up. You always helped me with homework, and read me bedtime stories, and you always have me feel better. You've always got a hot chocolate waiting and ready to listen._

 _Molly, you may not be my mum by DNA, but you definitely are in every other way. I'm a rare person in life who has the chance to get to pick who their mum is.  
Molly, I would pick you ever time._

 _I love you and want you to be my mum, so if you don't mind, would you adopt me so I can finally call you mum?_

 _Happy Mother's Day, Mum._

 _Lots of love,_

 _Lillian_.

Molly looked up from the letter with tears in her eyes. "But I thought you'd want to find your mother?"

"Why do I need to go looking for my mum when I'm looking right at her?"

Molly got more tears in her eyes. She got up and hugged her. "Of course I'll adopt you".

"I love you, Mum."  
Sherlock walked into the flat.  
"I take it she said yes to your request". They both looked at him and nodded. "Well, that's all good." He walked over to both of them and kissed them both on the forehead. He then sat down next to Molly.

"Oh, and on another note, I know you're together. I can hear you shagging. Please keep it down. It's not something a child wants to hear their parents doing."

"Or your landlady," Mrs Hudson said, choosing that moment to walk in. Both Molly and Sherlock looked at each other, not knowing how to process this information. "Also, Molly, on a side note, if you want any tips for in the bedroom, I have a lot of -"

"Yes, thank you, Mrs Hudson. Not in front of the child," Sherlock said, interrupting her before she got any further.

"Me, Dad, or the one that's going to be here in 8 months."

Everyone looked at Molly. Sherlock was impressed that his child saw it before he did. Molly sat there quietly, thinking 'great, there's going to be three of them'. She wouldn't have it any other way. She loved her family.


End file.
